Bone and Soft Tissue Pathology — Flashcards

Flashcard 81: Tennis racket cells in light microscopy seen in _____

Answer: Sarcoma botryoides

Flashcard 82: The pathophysiology of Paget's disease is increased bone _____

Answer: turnover

Flashcard 83: Pleomorphic cells surrounded by osteoid on histological examination is characteristic of _____

Answer: osteosarcoma

Flashcard 84: _____ fluorosis is seen at fluoride intake levels of 3-6mg/L

Answer: Skeletal

Flashcard 85: Osteopetrosis is due to mutation in the _____ gene leading to defective bone resorption

Answer: CLCN7

Flashcard 86: The clear cell and especially the mesenchymal variants of chondrosarcoma occur in _____ patients, in their teens or 20s

Answer: younger

Flashcard 87: _____ sequestrum is seen in tuberculosis of the rib.

Answer: Flake/feathery

Flashcard 88: Negatively birefringent crystals will appear _____ when aligned parallel to the slow axis of the compensator

Answer: yellow

Flashcard 89: _____ in chronic osteomyelitis is formed from deep layers of stripped periosteum

Answer: Involucrum

Flashcard 90: _____ is a calcium staining technique used to distinguish osteoid from mineralized bone.

Answer: Von Kossa stain

Extra: The **Von Kossa stain** is used to identify mineralized bone (stains black due to silver reduction by phosphates/carbonates), helping distinguish it from the non-mineralized **osteoid**. Another important stain for this purpose is **Goldner's Trichrome**, which colors mineralized bone green and osteoid red. *Note: While Von Kossa is technically a stain for the anions (phosphates/carbonates) associated with calcium, it is the standard method for demonstrating mineralization.*